Alloy steel



Allegheny and State of STATES FAEENT @FFEQE.

GEORGE W. SARGENT, OF PITTSBURGH, AND JOSEPH W. WEITZENKORN, OF WASH- INGTON, PENNSYLVANIA.

ALLOY STEEL.

No Drawing.

To all whom it may concern:

Be it known that we, GEORGE W. SARGENT, a resident of Pittsburgh in the county of lPennsylvania, and

JOSEPH W. WEITZENKORN, a resident of Washington, in the county of WVashington and State of Pennsylvania, have invented a new and useful Improvement in Alloy Steel, of which the following is a specification.

The object of the invention is to provide an improved manganese steel in which the desirable properties resulting from the use of manganese as a steel alloying element are increased and intensified, and in which the undesirable efifects of manganese are overcome or eliminated.

The steel alloy which we provide contains no more than about .80% carbon, from about 1.15% to 3% manganese, and from a fraction of 1% to 1.25% molybdenum. The remainder of the alloy is iron with the exception of impurities, such assulfur and phosphorus, WhlCh are usually found in steels. While the inventioncontemplates alloy steels of the range ofanalysis just stated, the preferred steel contains from about to .50% carbon, about 1.25% manganese and from about 25% to .75% molybdenum. 1

We have found that the addition to manganese steel of molybdenum in the ropor- 1,287,153, in which the flattened curves clearly illustrate the uniform physical properties of the steel when drawn within a wi e range of temperatures. The steel is also much less sensitive than usual manganese steels to heating other than in drawing.

It has also been found that not only does the molybdenum itself become evenly distributed throughout the steel, but also that the molybdenum has the effect of similarly Specification of Letters Patent.

Patented Dec. 2'7, 1921.

Application filed June 14, 1920. Serial No. 388,788.

1% of manganese it is not usually re arded as manganese steel. When alloye with steel in a large enough percentage to be considered a characteristic alloyin element, manganese adds considerably to t etensile strength of the steel, but this advantage is usually accompanied by a loss in reduction of area and in elongation.

Manganese alloy steels containing not more than aboutl% carbon, and manganese not exceeding more than about 3% to 4% are pearlitic, and hence are similar in some respects to the well known pearlit-ic nickel steels. The general belief is that such steels are brittle, but it has been found that the brittleness of pearlitic manganese steels is due largely to the failure or inability to heat treat them within the proper range of temperature. It has been found necessary to use great care in heat treating such steels to develop the desired physical properties, because a relatively small divergence from the temperaticularly suitable for case hardened articles.

When a low carbon alloy of the character explained iscase hardened, the case is of the hard and tough austenitic condition commoniy found in manganese high carbon steel, and the core is of very strong and tough pearlitic structure.

'We claim 1. An alloy steel consisting of not more than .80% carbon, from about 1.15% to 3.00% manganese, from a fraction of 1% to about 1.25% molybdenum, and the remainder iron.

2. An alloy steel consisting of from about 30% to .50% carbon, about 1.25% man- 

